There exists a plurality of the hypodermic syringe type injection device available for use. The vast majority of the devices are derivative of French physician Charles Pravaz' well-known design. The design consists of a cylinder body, a piston, and a hypodermic needle. This design works very well for introducing and extracting fluids from patients and has been adapted recently as a prefilled delivery method made suitable by following specific pre-determined safety protocols that add significant cost to the infusion equation.
Prefilled medical injection devices provide health care workers with a more efficient way to administer medications. The ubiquitous hypodermic syringe has seen a multitude of incremental advancements and improvements over the years in order to deal with the myriad of problems hypodermic syringes present in its manufacture, distribution, storage and use. Many of these advancements are unique to the problems relating to the prefilled syringe, which creates many new challenges because of the prefilled format. For example, prefilled hypodermic syringes face problems relating to chemical interactions with silicone, a common lubricant that allows the plunger to move down the cylinder, as well as adhesives, rubber, and tungsten. Further, transportation presents additional problems relating to atmospheric changes, creating a potential for pressure increases inside the cylinder body causing the device to extrude medication, wasting medication, while decreases cause the device to suction up outside air, which increases the risk of contamination. Many other problems exist in their use, such as the accidental removal or dislodgement of the plunger, as well as the potential for needle stick injury depending upon the type of needle used. This has been a problem to many health care professionals and has forced them to switch back to the vial syringe method for delivering vaccinations.
Although, there are multitudes of prior arts that incorporate solutions to the above problem the majority of them still carry a major disadvantage. The majority of injection devices require that the device be uncapped and recapped to avoid sticking others with a contaminated needle. The requirement to recap a syringe has created a major risk factor for healthcare workers, accidentally pricking themselves with a soiled needle.
It is therefore an object of the present invention to introduce a device that is prefilled with medication, adjusts to changes in ambient temperature and pressure, while providing a risk reducing mechanism to inject patients. Additionally, the invention is designed for a mass production method (Blow-Fill-Seal method) that minimizes the risk of contamination. Blow-Fill-Seal has numerous requirements and limitations and the ampoule and collar (insertion technology) have both been designed to be compatible with Blow-Fill-Seal manufacturing. This design combines the separate plastic syringe manufacturing process and the subsequent filling of the syringe with a liquid in a separate filling process. Currently the prefilled syringe concept uses two or more separate and distinct machines to create a prefilled syringe with a rubber stopper inside the syringe. None of these devices have a rubber stopper which is used to push the liquid out the end.